The present invention relates to the field of vacuum interrupters and is to be applied in the structural design of a contact configuration which comprises two axially opposed contacts, whereby each contact has a cup-shaped design and is provided with a support structure for the contact plate.
A known contact configuration for a vacuum interrupter consists of two contacts which are arranged equiaxially and are able to move relative to each other in their axial direction, and having contact carriers which are provided with a current-supplying stud have a cup-shaped design and provided with tilted slots to generate an axial magnetic field (axial field contacts). On the rim of each contact carrier wall, a contact plate consisting of a contact material is soldered onto a chromium-copper base. In order to mechanically stabilize the contact, a basically columnar support which consists of material with poor electrical conductivity, e.g., of a nonmagnetic material such as chromium nickel steel, is provided between the slotted contact carrier and the equally slotted contact plate. This support is centrally mounted and in cross section approximately has the shape of an H-armature carrier (DE-A-32 31 593). In the case of other known contact configurations, the support, which is also basically columnar, is widened in an umbrellalike manner only at the end which is turned towards the contact plate (DE-A-33 34 493), or it has a relatively narrow supporting core and is provided at the ends of this supporting core with plate-like supporting parts (EP-A-0 155 376). In these types of contact configurations, there is a concentration of current in the region of the supports when the contact is closed that can cause the contacts to fuse together when rated short-time withstand currents occur which are greater than 50 kA. This type of fusing can also occur when the support is designed as a hollow cylinder which is mounted on a graduated circle corresponding to the average wall diameter of the hollow cylinder within the cross-sectional area of the current-supplying stud while leaving free a central cross-sectional region (DE-OS 32 27 482). In this connection, the disadvantage of having a relatively large shunt across the support continues to exist, whereby the formation of an effective axial magnetic field is obstructed.